Ecosystem Interactions

1
Ecosystem Interactions

• Environmental Science

2
What Shapes Ecosystems

• Abiotic and Biotic Factors
• Habitat physical location where an organism
  lives
• Niche the use of the habitat by an organism
  (includes food, physical location, how it
  interacts with other organisms, etc.)

3
Species Interactions
4
Ways in Which Species Interact

• These categories are based on whether each
  species causes benefit or harm to the other
  species.
• Other types of interactions are possible.
• Many interactions between species are indirect,
  some interactions do not fit in a category
  clearly, and other types seem possible but are
  rarely found. Therefore, many interactions are
  neither categorized nor well studied.

5
Competition

• Competition when different individuals or
  populations attempt to use the same resource
• Within a species food, mates, territory
• Between species food, water
• Competition can occur even if the individuals
  never meet.
• Flowers competing for the same pollinators

6
Community Interactions - Competition

• When members of different species compete for the
  same resources, we say that their niches overlap.
• These species will divide up the resources either
  by time or space called niche restriction
• Ex. Warblers in coniferous trees will live only
  on certain levels of the trees
• Ex. Diurnal v. Nocturnal insects - both need the
  same resources, but some are only active in the
  day and others at night

7
Community Interactions - Predation

• Predator/Prey Relationship
• Predator organism that hunts/kills
• Prey organism that is food (e.g. cat and mouse)
• Sometime one predator may also be another
  organisms prey

8
Specialists v. Generalists

• Species that eat mostly one type of prey are
  called specialists
• Ex. Canadian Lynx and the Snowshoe Hare
• Generalists will eat whatever is easiest to find
  and capture
• Ex. Coyotes or Wolves

9
Symbiosis and Coevolution

• Symbiosis two species who live closely together
• Overtime, species in close relationships may
  coevolve. These species may evolve adaptations
  that reduce the harm or improve the benefit of
  the relationship.

10
Mutualism

• Mutualism symbiosis in which both organisms
  benefit often each species depends on the other
• Ex. Flowers and their pollinators

11
Commensalism

• Commensalism symbiosis in which one organism
  benefits and the other is neither helped nor
  harmed.
• Even seemingly harmless activity, however, might
  have an effect on another species.

Ex. Barnacles on a whales skin or Birds nesting
in trees
12
Parasitism

• Parasitism symbiosis in which one organism is
  helped and one is harmed
• Parasite the organism that feeds on another
  organism
• Host the organism parasite takes its
  nourishment from
• Ex. Fleas and ticks

The difference between a parasite and a predator
is that a parasite does not usually kill its
host.